Hackers declare war on international forensics tool

Hackers have released software they say sabotages a suite of forensics utilities Microsoft provides for free to hundreds of law enforcement agencies across the globe.

Decaf is a light-weight application that monitors Windows systems for the presence of COFEE, a bundle of some 150 point-and-click tools used by police to collect digital evidence at crime scenes. When a USB stick containing the Microsoft software is attached to a protected PC, Decaf automatically executes a variety of countermeasures.

"We want to promote a healthy unrestricted free flow of internet traffic and show why law enforcement should not solely rely on Microsoft to automate their intelligent evidence finding," one of the two hackers behind Decaf told The Register in explaining the objective of the project.

Microsoft has been pouring free COFEE to law enforcement officers since at least mid 2007. Short for Computer Online Forensic Evidence Extractor, it packages forensics tools onto an easy-to-use USB stick that allows investigators to collect browsing history, temporary files and other sensitive data from most Windows-based machines. COFEE is distributed through Interpol.

Last month, when COFEE leaked to the net, Microsoft downplayed concerns the breach would allow hackers to create countermeasures. Redmond representatives weren't immediately available for comment late Sunday night.

Decaf boasts a huge variety of user-driven countermeasures against COFEE. In addition to nuking temporary files within seconds of detecting files or processes associated with the investigative tool, Decaf can also clear all COFEE logs, disable USB drives, and contaminate or spoof a variety of MAC addresses. Future versions promise to add features that allow users to remotely lock down protected systems.

The software began seeding on private BitTorrent trackers on Sunday afternoon, and shortly thereafter, it was posted here. The Register wasn't able to immediately analyze the 181 KB executable to confirm it performed as advertised.

While the hackers are making available the Decaf executable, they are not releasing the source code for fear, they say, that the signatures used will be reverse engineered. The end user license agreement that accompanies the software states: "You will not disassemble, decompile, or reverse engineer it, in whole or in part, except to the extent expressly permitted by law. You will not use DECAF for illegal purposes. You will comply with all export laws. DECAF is licensed, not sold." ®